DetailsGilbert Yeung of Blue Circle Audio, in a short decade has turned out more
than his share of classic products, and in my opinion none is finer than the BC6
single-ended, hybrid power amplifier that I have used as a reference for the
last five or six years. From a beginning with a product line built around low
output power amplifiers and tweaky pre-amplifiers, Blue Circle has grown to
offer a full line of power, pre-amplifier and phono stages that has consistently
received glowing reviews. Still, something was missing  a source. At shows
Blue Circle has often demo'd using their in-house (i.e. not for sale) test-bed
DAC, the AG9000, but with the release of the BC501, Blue Circle has completed
their electronic lineup.

With
a full-size chassis (17.25 inches wide, 3.75 inches high, 16 inches deep
including the input selector), the BC501 is a solid and solid-looking piece.
Round back the Blue Circle is nothing if not accommodating with three digital
inputs  ST optical, RCA, and AES/EBU  and two outputs  single-ended RCA
and balanced AES/EBU. The power cord receptacle is a hospital grade Neutrik-styled
adaptor (Blue Circle supplies its own power cord). The front panel has the
familiar glowing blue circle in the center that lights up when you power her up.
The left side of the panel has an LED to indicate de-emphasis, and a toggle
switch to select phase with an LED to display your choice. The right side has a
signal lock indicator and a large brushed steel input selector. It's an
asymmetrical design, but when that blue circle lights up, it looks good.

Inside,
the BC501 shows Gilbert Yeung's fanatical attention to detail as every part,
wire and board is overspec'ed and finished to Swiss watch perfection. The DAC
itself is a 24 bit, 8x unit in a BiCMOS sign-magnitude architecture. What that
last part means, you'll have to ask Mr. Yeung directly, but the claim is that
this design greatly reduces digital noise resulting in great detail retrieval
and a lower noise floor.

To discover how good the BC501 is, I used the following gear. Other digital
sources were a Cary CD-303/200, a Berendsen CD1 and my extremely customized
Assemblage DAC1. The reference pre-amplifier was my First Sound Presence
Statement while a ModWright SWL 9.0SE also saw a considerable amount of time in
the system. Power came from an Art Audio Carissa and a Blue Circle BC6, while
loudspeakers were my reference Merlin VSM-Ms, Triangle Antals, Audiophysic
Scorpios and DeVore Fidelity Gibbon Super 8s. Cabling was from Cardas, Acoustic
Zen, Audio Magic, Stereovox and Shunyata Research  who also supplied power
conditioning. With all that out of the way, the real question is, what does it
sound like?

More DetailsFirst, let me point out again that I have used a Blue Circle BC6 power
amplifier as a near constant reference for about 7 years. Why, and why not one
of the more recent Blue Circle amplifier designs? First, because the BC6 is one
of a mere handful of truly great audio products to come from the 90s. It was
so good that in its power and price range I have yet to hear any solid-state
amplifier its equal, much less anything that bests it. The reason the BC6 is so
good may be because Mr. Yeung has consistently does his finest work on small
signal devices or at least on devices where everything can be run flat out 
so the hybrid (tubed input stage, solid-state output stage), pure 'Class A,' 25
watt per channel BC6 allows Yeung to do what he does best, which is deliver a
high purity signal loaded with detail and dynamics, but also one that delivers a
direct dose of 100 percent of the emotion in any particular recording. In
listening to Blue Circle over the years I have nearly always heard that same
sound in their pre-amplifiers  as have others as they continue to receive
constant, positive reviews for their pre-amplifiers  but when the company
moved to higher powered, non-pure class A amplifiers in the late 90s I felt
they lost a touch of the emotion on the power side. In the last several years
they seem to have found their way back with the big amplifiers, and so I have
been interested in checking out their power products again. But when I saw a
commercial DAC from the company, given their past history with small signal
devices I knew it had the potential to be real special. Which brings us yet
again to the main point here, what does it sound like?

Well, in a word it sounds natural, and if you've been bored enough to read my
opinions over the years you know that is about as high a piece of praise as I
can summon. Then again, even if you have been following events at the Warnke
Music and Hiking Lodge I'm guessing you want more info, so here goes.

Deeper DetailsAt the top end the BC501 has the absolute best treble I've heard. Its dynamic
scaling is explosive and yet never, ever brittle, sharp or thin. This is not a
skill to be slighted. Go listen to live, acoustic music and you'll hear a lot of
treble information, much of it at high SPLs (cymbals anyone?) and yet, while it
may startle, it's not the ear bleeding stuff we usually get from our stereos.
Think about that for a second  when you listen to live music it is usually
the bass that constrains how loud you can listen and enjoy, but in your
listening room it is usually the treble that makes you leap for the volume knob.
Well, with the BC501 that was not the case. Take a song like the Jeff Buckley
track "Last Goodbye" from Grace [Columbia CK 57528] which opens
with little guitar riff in the right channel, adds a chugging bass line and then
leaps into action with a spray of cymbals. Through my Assemblage this spray is
like an icy wave crashing over the bow of on an Arctic trawler, but with the
BC6, though just as loud it is like the warm surf smashing into you at the
beach. You want less a poetic description? Ok, with the Assemblage in the system
the volume limit for the song is set by those cymbal splashes as they have a
leading edge that is harder to listen to than real cymbals, but with the BC501
the track can be played louder because the cymbals can leap up in volume without
hurting your ears, whilst also retaining a pure and natural timbre  just like
the real things.

Dropping down the spectrum, the mids of the BC501 have that smooth,
continuous quality that blurs the line between digital and analog. Feed the
BC501 a great recording, like the Charles Lloyd disk, The Call [ECM
1522], whose opening track "Nocturne" begins with gentle cymbals, a
lovely tenor solo by Lloyd and a flowing solo by Bobo Stenson on piano, and you
can hear what I mean. Lloyd's sax is rich with harmonic information, fully
fleshed out and vivid. Reed and metal exist as separate entities and yet combine
to create a warm, inviting and very real tonality. Stenson's piano, likewise, is
string and wood with each part detailed, but conjoined in song as well.

Bass, even on some of the more driven and bizarre electronica I enjoy, is
taut and scarily tuneful. Lustmord's The Place Where the Black Stars Hang
[Side Effects DFX 16] is full of dread, even on a boombox, but with the BC501
the deep bass machine throbs are revealed in full glory  the processed but
recognizable sounds are placed so far back in the stage that they seem like a
nightmare and yet are so real that your palms begin to feel clammy. Good stuff.

Back in the real world, the 1986 film Round Midnight [Columbia CK
40464], besides reminding America of Dexter Gordon, featured an amazing lineup
in a live recording that just blazes. Bass duty is shared between Ron Carter and
Pierre Michelot, and both shine. The version of How Long Has This Been Going On
from the original release opens with Herbie Hancock down low on the keyboard and
then continues with he and Michelot sliding in and out of sync as they play a
similar low bass pattern. Through the BC501 the subtle textures of each
instrument was easy to pick out, and yet not so analytical that the music was
lost.

Dynamically, the Blue Circle is a good un. As I mentioned earlier, the
treble scales from ppp to FFF with snap and drive. Likewise the mids showcase
all possible ranges in volume with ease. Bass, at least in my system, was very
linear but lacked just a touch of the explosive power that the BC501 was able to
deliver in the upper ranges.

If you've been following along at home, you know I'm not that much of a
staging freak, though I enjoy the stuff when it works. In this regards, the
BC501 more than met my expectations. Left to right spread was very nice, with
dense and stable images. Depth, likewise, was far better than the norm and very
solid. Images on the stage had particular beauty, resolution and grace.

Other DetailsCompared to other players in my system, such as the Berendsen and the Cary,
the BC501 generated a deeper emotional connection to music. This is not to imply
that it lacked detail or warmed things up in a tube-like manner, to the
contrary, it had a cleaner, more detailed stage than the other players 
rather, the magic of the BC501 lies in that word I used earlier, natural, as the
Blue Circle allowed me to sink more easily into the illusion created in my
listening room. To be sure, the other players are skilled and each has at least
one area where they show their heels to the BC501.

Compared to the BC501, the first thing the Cary makes you notice is its bass.
Though a tonally even player, with linear dynamics, the Cary has deeper bass
with slightly better definition and dynamics than the BC501. On rock and some
jazz, this gives the Cary an edge over the BC501, but on everything else the
superior mids and treble, dynamics and tonal purity of the BC501 takes over.

Since the Berendsen is still awaiting a formal review I'll limit my comments
about it somewhat, but what the German player offers is a very coherent,
sophisticated sound, with great detail and even dynamics. As compared to the
BC501, it has a similar set of strengths with, perhaps, just a slight veil over
the top but with deeper bass reproduction. In the end I preferred the slightly
more open, more detailed and more emotionally direct BC501, but the strengths of
the Berendsen are very seductive.

Final DetailsI have spent a great many years listening to Blue Circle gear and have come
to appreciate the care Gilbert Yeung lavishes on his products. Naturalness and
purity are long-term hallmarks of his designs, and the BC501 confirms its
lineage. The BC501, like the BC6, is the perfect combination of a reviewer and
music lover tool. Want to explore a recording? The BC501 is the perfect partner
to pull out all the detail you want. But (more importantly) want to relax,
rejuvenate and rejoice in music? There too, the BC501 is a willing and perfect
partner. And at the performance the BC501 returns for the price, it is a steal.
The ability to use up to three different digital sources is a real bonus  I
often hooked both my computer and transport up at the same time. Add in a build
quality that will assure a trip to the hospital (and not the repair shop) if you
drop it on your toes, and you have a true digital bargain. Most highly
recommended.